This invention relates generally to an apparatus for separating earthen material containing rocks or stones from soil and, more particularly, to a machine that can receive quantities of waste material from a quarry and extract the desired rocks or stones therefrom by separating out the clay, mud or dirt.
Quarries, such as limestone quarries and the like, produce a stone product in a variety of configurations. Such stone product can be utilized in a variety of known different ways, including concrete aggregate, asphalt paving aggregate, concrete blocks, etc. Stone aggregate is used as base material in concrete and asphalt paving, beneath footers and basement of buildings and many other similar known uses. Limestone, particularly when finely crushed, is used as a soil additive in agricultural applications and, if of a very high calcium content, can even be finely processed to be used in cosmetics.
Mining or quarry operations operate to extract the desired stone from the ground in a number of different manners, including boring and stripping. In a quarry, for example, a hole is dug into the ground to remove the soil and stone. Blasting is often utilized to loosen the rock and permit removal thereof. Loaders collect the rock and soil and trucks remove the material to a processing or crushing plant for further processing. In the blasting process, particularly, rock is typically discharged onto the quarry floor where it can become mixed with clay, mud and soil to contaminate the material.
Clay, mud and soil is also found naturally with the rock material when extracted from the ground. Unless the rock material can be adequately separated from the clay, mud and soil the material cannot be sent to the crushing plant as the finished product will be similarly contaminated. Accordingly, contaminates such as clay, mud and soil are unacceptable and substantial amounts thereof render material unusable.
Quarries have typically discarded materials that are deemed to be too heavily contaminated with clay, mud and soil. Generally, such contaminated materials are transported to a designated dump site and stockpiled as rubble. Occasionally, the largest of the rocks are picked from the discarded rubble with traditional equipment, such as a loader or a backhoe. Such activities are quite labor intensive and are not cost effective for the amount of recoverable material that can be gleaned from the operation. Some quarries have tried to utilize screening machines to sift through the discarded rubble, but such machines tend to plug or clog with the contaminates and are thereby rendered useless.
Accordingly, it would be highly desirable to provide an apparatus that could effectively and economically separate the contaminating clay, mud and soil from rocks found in the discarded rubble.